Designs and applications of periodically loaded modeless integrated circuit subtrates.

摘要

In recent years, there has been significant interest in surface-wave elimination in all-planar directions through the use of periodic elements incorporated into integrated circuit structures. However, to date there is no comprehensive theory for the design of the surface wave bandgap and leaky modes with complex propagation constants have not been properly taken into account. As shown here, fast periodic leaky modes may exist within a surface-wave bandgap zone. These leaky modes may result in more energy loss and cross talk than the surface-wave modes; therefore it should be taken into account in circuit design for the planed performance.; Thesis presents theory and experimental validation for guided surface-waves and leaky modes on a structure consisting of planar periodic metal elements over a grounded substrate and discusses their uses as a potential substrate for MICs (Microwave Integrate Circuits). In fact, application of periodic structures containing metallic component has been of less interest as compare to the application of using a dielectric PBG material. This is mainly due to the perceived problems of lossiness in the metal elements. However, periodic structure with metallic element provides distinct advantages over their dielectric counterparts. The existence of surface-wave bandgap and leaky modes is attributed to either resonance of metallic element or the weakly bounded dielectric slab modes. It is also found that fast periodic leaky modes may exist within a surface-wave bandgap zone.; Design consideration with variation of structural profile for achieving a complete surface-wave bandgap without leaky-modes (modeless) bandgap are discussed and examples are provided. Implementations of proposed modeless substrate into the MICs are presented.